Reproductive Hormones + Testosterone Flashcards by Dave Colline Andrade

Two sex steroids

Androgen and Estrogen

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Precursor hormone of estrogen

Weak Androgen

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Both androgen and estrogen comes from?

Cholesterol

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Ovary for women converts:

Testosterone to Estradiol

Androstenedione to Estrone

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Peripheral tissues!

Reduces testosterone to dihydrotestosterone
Hydroxylate estradiol to estriol
Converts adrenal androgens to androgens

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Physiology of Testicles

Spermatogonia - Haploid cells - Mature Sperm

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Where sperm develops and matures

Sertoli Cells

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For the maturation of a mature sperm, it has to undergo

Mitosis and meiosis

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3 Major Transport Proteins

Albumin, Sex Hormone Binding Globulin, Corticosteroid Binding Globulin

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Transport of Androgens and Estrogen

SHBG

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Delivery of progesterone and Glucocorticoid

CBG

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Percentage of hormones bind to Albumin

98 to 99

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Percent of free steroids

1-2

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What do you call active sex steroids

Free steroids

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Steps in Hormonal Control of Testicular Function

Pulsatile generation of GnRH
Release of GnRH into the portal hypophyseal system
Production of LH and FSH from the adenohypophysis
Testicular Steroidogenesis

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Pulsatile generation is

Regular production or periodic increase or decrease in a specific time when they released

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GnRH will be delivered to

Adenohypophysis

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Impaired generation of pulse leads to

Hypogonadism

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What is Testicular Steroidogenesis

LH and FSH stimulates gonads to release certain hormones

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It is also made from cholesterol, produced in the body by the adrenal gland

Pregnenolone

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Starting material for the production of male hormones

Pregnenolone

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Steps of Testicular Steroidogenesis

Trapping pf Cholesterol by endocytosis
LH receptor binding
Production of intracellular cAMP
Activation of protein kinase
Protein phosphorylation
Testosterone synthesis

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Two sources of cholesterol

Lipoproteins and Leydig Cells

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Leydig cells are regulated by the

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Major androgen hormone in the blood

Testosterone

Regulators of Testosterone

1. FSH stimulate protein synthesis | 2. LH for Leydig Cells

LH and FSH has the same…

Alpha subunit with TSH and hCG

LH and FAH shares a

Synergistic function

What is the function of testosterone

Growth and development of the reproductive system, prostate, and genitalia

Testosterone together with …. Provides a feedback control mechanism

Inhibin

Highest Level of Testosterone

6 AM

Lowest Level of Testosterone

12 AM

Individual is in deep sleep

Lowest level of Testosterone

What is the average decline of testosterone

110 ng/dL every decade

Tests for male infertility

Semen analysis, testosterone, FSH, and LH

Testosterone transport proteins

SHBG 50% | Albumin 45%

In prenatal development: Exposure of testosterone to the

Wolffian duct leads to male genital tract

In prenatal development for females, the production of this hormone aids in the regression of the female primordial genital tract

Anti Mullerian Hormone

Sertoli cells of Females will only produce AMH if it is

Acted by the FSH

Low level of AMH

No regression of the female primordial genital tract thus leads to development of both sexes

Postnatal development for testosterone

Development of sexual characteristics

It stimulates the production of testosterone

Two hormones that induces spermatogenesis

Fsh and testosterone

Overuse of exogenous testosterone will lead to

Low sperm production

Considered as Secondary Hypogonadism

Pre Testicular Infertility

Decreased FSH and LH - Decreased Testosterone

Pre Testicular Infertility

Problem in the testicles - Low FSH AND LH

Testicular Infertility

Testicular Infertility or

Primary hypogonadism

One or two testes fail to descent from the abdomen into the scrotum

Cyptorchidism

Problem in the transport and function of sperm cells

Klinefelters Syndrome

Congenital Testicular Infertility that has normal testosterone, lh and fsh

Klinefelters Syndrome

Enzyme that converts testosterone to DHT

5 alpha reductase

No problem in the testicle, problem is in the transport or function of the sperm cells

Post Testicular Infertility

Decreased testosterone, increased fsh and lh

Hypergonadotropic hypogonadism

Low levels of testosterone and FSH LH

Hypogonadotropic hypogonadism

Conditions under hyper-hypo

Klinefelters, testicular feminization syndrome, 5 alpha reductase deficiency, myotonic dystrophy, testicular injury and infection, sertoli cell only syndrome

Caused by presence of extra chromosome

Klinefelters Syndrome

Hormone important to produce protein Inhibin

FSH

Once LH and FSH elevates, greater activity of the enzyme? It is also used to convert testosterone to estradiol

Aromatase

Klinefleters Syndrome characterized by:

1. Small and firm testes 2. Gynecomastia 3. Azoospermia 4. Reduced bone density

Also known as Testicular Feminization Syndrome

Androgen insensitivity syndrome

Cause of Testicular Feminization Syndrome

Mutations of the androgen receptor and impaired androgen actions in the tissue

Lab Tests for Testicular Feminization Syndrome

Increase testosterone, Increase Gonadotropins

5 alpha reductase deficiency

Mutation encoding the type 2 isoenzyme

Important for the development of prostate and external genitalia of men

DHT

Myotonic Dystrophy

Primary gonadism, frontal balding, diabetes, muscle weakness, atrophy, dystonia

Myotonic Dystrophy

Primary hypogonoadism: increased Fsh | Later stage: decreased testosterone increased Lh

Mumps occurring after puberty can lead to

Mumps orchitis and permanent testicular injury

Lack of germ cells, high fsh but normal testosterone

Sertoli Cell Only Syndrome

Conditions of Hypogonadotropic Hypogonadism

Kallmans Syndrome, Hyperprolactinemia, Type 2 diabetes, pituitary disease

Inherited X Linked Recessive Trait that manifests hypogonadism during puberty

Kallmans Syndrome

Associated effects of Kallmans Syndrome

Anosmia (inability to smell) and midline defects that include cleft palate and cleft lip

What is it in prolactinemia?

Increased prolactin, can result to hypogonadism

Type 2 Diabetes what is it

Lh decreased, testosterone decrease because of insulin resistance and high crp level

Other causes of Hypogonadotropic Hypogonadism

Age and pituitary disease

What is in primary hypogonadism

Elevated levels of FSH and LH but low testosterone

What is secondary hypogonadism

Normal or Low levels of gonadotropins and hormones

Tertiary Hypogonadism?

Problem in the hypothalamus, normal or low levels of gonadotropins and low testosterone

Hypogonadism is collected between

8 10 am

Reproductive Hormones + Testosterone Flashcards

(79 cards)